1. Field of the Invention
The present invention relates to a toilet flush water supply device, and more particularly to a toilet flush water supply device for supplying flush water to a flush toilet.
2. Description of the Related Art
Toilets in which a rim water spout port and a jet water spout port are formed in the bowl portion of a flush toilet and water is supplied to said water spout ports to discharge waste by siphon action have been conventionally known. Such flush toilets may be divided into those in which flush water is directly supplied from a water supply source (e.g. water main), and those in which flush water is supplied from a flush water tank provided on the flush toilet where it is stored.
As an example of a flush toilet furnished with such a flush water tank, JP-A-2006-274540 discloses a flush toilet flush water supply device provided with a ball tap (water supply valve) having a pilot-type diaphragm valve in a flush water tank for supplying flush water into a flush water tank from an external water supply source (water main).
In the toilet flush water supply device used in the toilet set forth in JP-A-2006-274540, a ball tap (water supply valve) having a pilot-type diaphragm valve is formed at the top end of a water supply pipe connected to an external water supply source (water main), such that a float penetrates the water supply pipe and is capable of up or down movement.
Because the float is attached by penetrating the water supply pipe in a toilet flush water supply device of this structure, assembly of the device is undesirably complicated. Also, when the float rises with the rise of the flush water level, there is a large amount of looseness such that the float is unable to rise smoothly. Moreover, when the float rises and the diaphragm valve pilot hole is blocked so as to switch from spouting to stopping water, fluctuations in supply water pressure, flush water level, and the like cause fluctuations in the downward pushing force (downward) blocking the pilot hole, and the buoyancy (upward) of the float, thereby causing a hunting phenomenon to arise leading to vibration and anomalous noise as the float vibrates. This has been a problem particularly with high supply source water pressure, increasing the tendency for the hunting phenomenon to occur.